1. Field of Invention
The present invention pertains to the field of bicycle brakes. More particularly, this invention is a pedal actuated bicycle brake system for actuating a supplemental brake of conventional technology associated with either or both of the front and rear wheels of a bicycle by rotating the pedals of the bicycle in reverse, thereby increasing the brake effectiveness.
2. Description of the Related Art
Bicycles are known to have several different types of brakes and braking systems. Typically brakes are actuated either via a hand lever located on the handle bars or via the pedals. Coaster brakes are common especially in single-speed bicycles. This type of braking system is actuated by back-pedaling, which actuates a braking mechanism internal to a wheel hub. Accordingly, coaster brakes are disposed in the rear wheel hub.
With the advent of multi-speed bicycles, hand-operated brakes have become more prominent due to incompatible technologies. Specifically, coaster brake technology was not compatible with that multi-speed technology. Since the introduction of the multi-speed bicycle, technology has been developed where both the coaster brake technology and the new multi-speed technology has been incorporated in the same wheel hub. At the same time, rim and disc brake technology has advanced to a point where they have certain advantages over coaster brakes. It has been shown that coaster brakes are susceptible to over-heating to a point of permanent damage on long steep downgrades while rim brakes show only a modest increase in temperature. However, a major advantage of coaster brakes is that they are pedal-activated, removing the burden of holding a hand-actuated system.
Typical braking systems of the art are those devices disclosed in the following U.S. Patents:
U.S. Pat. No.Inventor(s)Issue Date3,782,507R. L. ShreveJan. 1, 19744,020,925J. W. Ryan et al.May 3, 19774,182,194Y. TomozawaJan. 8, 19804,260,044E. E. FosterApr. 7, 19814,313,530W. BoydFeb. 2, 19824,462,488W. BoydJul. 31, 19844,598,805S. TomozawaJul. 8, 19865,027,930B. E. ReedJul. 2, 19915,064,035K. TsuchieNov. 12, 19916,029,780J. PhillipsFeb. 29, 2000
Of these patents, Shreve, in his '507 patent, discloses a brake actuating mechanism for a two wheeled vehicle such as a motorcycle having front and rear brakes. The '507 mechanism sequentially operates the front and rear brakes upon actuation of a brake pedal, with the rear brake being applied before the front brake in order to minimize instability and loss of vehicle control. While the rear brake is operated by the brake pedal, Shreve discloses that the front brake is actuated by either or both of the brake pedal or a hand lever mounted on the handle bar. Shreve uses conventional brakes in association with the '507 brake actuating mechanism.
In the '925 patent, Ryan et al., teach a bicycle braking system wherein both front and rear wheels are equipped with a coaster brake. Flexible connections are provided between a reaction torque arm of the rear coaster brake and the front brake for applying the front brake. Interposed in the connections is a proportioning lever mechanism for adjustably controlling the amount of braking effect transmitted to the front brake. Flexible connections are provided from the reaction torque arm of the front brake back to the lever mechanism for applying a feedback increment of actuation to the front brake.
Y. Tomozawa, in the '194 patent, discloses a multi-speed free wheel hub with a coaster brake for use in a bicycle. The hub includes a driving mechanism for driving the bicycle and a braking mechanism for braking the bicycle, each independent of the other. A driving female screw cylinder is incorporated into the driving mechanism to achieve the complete driving and braking modes of operation. As in conventional coaster brakes, the braking mechanism is engaged by the rider by back-pedaling.
Foster ('044) teaches a bicycle having front and rear wheel caliper brakes operated via a pedal crank assembly. The pedal crank assembly includes a shaft extending through a hub and connected to pedal cranks. The bicycle also includes a brake control assembly having a cam mounted on the shaft outwardly of the hub for rotation with the shaft, the cam having at least one working edge surface. A plate carried on the shaft is in substantially planar parallel relationship to the cam. The plate pivotally mounts a cam follower for engaging the cam working edge when the rider of the bicycle back pedals. A substantially vertically extending rod is loosely engaged at its lower end to the plate and fixedly engaged in its upper end portion to brake control cables leading from the caliper brakes. The rod is journaled for axial rotation and resilient means urges the same into spaced relationship with respect to the cam follower with which the rod is engageable upon rotation for releasing the cam follower from engagement with the cam.
In his '530 patent, Boyd discloses a coaster brake for a bicycle. The coaster brake includes a brake operating lever consisting of a yoke and an integral arm coupled to the pedal crankshaft of the bicycle by a self-acting unidirectional friction clutch, formed by a coil spring embracing the crankshaft. The spring includes two portions, with one being disposed on either side of the yoke. The lever moves a brake actuating rod or cable actuating a wheel brake which may be of several different types.
In his '488 patent, Boyd discloses a bicycle braking system incorporating a pedal crankshaft operated brake actuator. A lost motion connection is provided in the chain drive to the rear wheel of the bicycle, the lost motion being taken up by a highly progressive spring of sufficient strength to require a significant proportion of normal pedaling torque to overcome its action. Also provided is a brake incorporating a resilient stirrup supported at three points distributed around the rim of the rear wheel of the bicycle, the stirrup arms being subjected to a wedging action upon actuation of the brake causing brake shoes mounted on the stirrup to grip the rim of the wheel with a caliper action.
S. Tomozawa, in the '805 patent, discloses a typical coaster brake having a screw cone provided with a tapered part. The tapered part is cooperatively threaded to mate in an internal end part of a male screw cylinder to which a chain gear is fixed. The screw cone is removed by means of the rotation of the male screw cylinder. A brake shoe is in mesh with a fixed brake cone which is provided outwardly of the screw cone to engage with a hub body by pressing the brake shoe being expanded.
Reed discloses in the '930 patent a coaster brake assembly which is coupled directly to a drive shaft. The drive shaft has a threaded driver integral thereon. A clutch cone having internal threads traverses in axial directions as it threads on or off the driver depending on the rotation of the driver. A brake cone is provided which has a smooth axial bore through which the drive shaft rotates. The axial movement of the clutch cone toward the brake cone operates to force brake shoes against the inside wall of the hub. A spring is provided to facilitate threading action between the clutch cone and the driver.
In the '035 issued to Tsuchie, a coaster brake is provided with a clutch cone screw-fitted to a driving body which is driven by pedals, to be axially movable in correspondence with the driving body's turning direction. A brake cone is supported through a clutch mechanism which is limited to rotation in the reverse direction. A brake member is operated to apply a brake on the hub shell by the clutch cone moving to approach the brake cone side, when the driving body is turned in a reverse direction. When the hub shell is turning in the forward direction, the brake action may be exhibited by applying to the driving body reverse rotation similarly top conventional coaster brake. The brake cone is rotatable in the reverse direction by means of the clutch mechanism and as the driving body is subjected to a reverse turning. When the hub shell is not turning in the forward direction, the brake cone will turn in the reverse direction integrally together with the driving body, the clutch cone and the brake member and in concert with the hub shell. Thus, the coaster brake mechanism operates as a reverse driving mechanism.
Finally, the '780 device taught by Phillips is a crank assembly for a chain driven mechanism such as a bicycle. The crank assembly has at one end of a crank arm, a journal adapted for engagement with an axle. The axle has at its other end a connection. The one end of the crank arm has mounted thereon a housing via a unidirectional variable clutch, the housing having an extension to which, in use, an activation means such one or more brake cables are attached. The arrangement is such that during normal forward rotation the crank arm moves normally and the housing is stationary relative thereto, while during back or reverse movement of the crank arm the housing moves to activate the brake cable or cable means.